基于互联和阻尼分配跟踪的孤岛微电网非线性电压功率控制

Nonlinear Voltage and Power Control of Isolated Island Microgrids Based on Interconnection and Damping Distribution Tracking

针对孤岛微电网中分布式电源变换器应对大扰动能力差、扰动过程中电压和功率波动大、且无法回到原始运行状态等问题,该文提出了一种适用于孤岛微电网中多分布式电源变换器的非线性跟踪控制方法。该控制方法基于同步参照系(synchronous reference frame,SRF)中的互联和阻尼分配无源控制器(interconnection and damping assignment passivity-based controller,IDA-PBC)进行设计,该控制器负责控制微网内功率转换装置(power conversion units,PCU)的动态特性。PCU包括DC/DC升压变换器通过互连电容与DC/AC逆变器耦合,并通过LC滤波器连接到电网。该控制器使PCU在系统运行点变化期间平滑地抑制电压/电流和有功/无功功率的变化,同时精确地跟踪由下垂控制器产生的参考指令。最后,在多源孤岛微网上对PCU进行了时域仿真分析,将所提方法与PI控制器以及现有非线性控制策略进行比较,仿真结果表明,所提方法能较好地抑制大扰动下微网的电压、电流以及功率波动,控制效果明显优于PI控制和其他非线性控制。

In this paper,a nonlinear tracking control method for multi-distributed power converters in isolated island microgrids is proposed to solve the problems such as poor ability of distributed power converters to deal with large disturbances,large voltage and power fluctuations during the disturbance process,and the inability to return to the original operating state.The control method is designed based on the interconnection and damping assignment passivity-based controller(IDA-PBC)of the synchronous Reference frame(SRF)is designed.The controller is responsible for controlling the dynamic characteristics of the power conversion units(PCU)in the micro grid.The PCU consists of a DC/DC boost converter coupled to a DC/AC inverter via an interconnect capacitor and connected to the grid via an LC filter.The controller enables the PCU to smoothly suppress voltage/current and active/reactive power changes during system operating point changes,while accurately tracking the reference instructions generated by the droop controller.Finally,time-domain simulation analysis is carried out for the PCU on a lonely island microgrid of the multi-source,the proposed method is compared with PI controller and current nonlinear control strategy,the simulation results show that the proposed method can suppress micro network under large disturbance voltage,current and power fluctuations,the control effect is better than PI control and other nonlinear control.